DESCRIPTION: (Applicant's Abstract) The applicant is requesting five years of funding through the Mentored Career Development Award (KO1) program to enhance her methodological skills to conduct longitudinal research on the co-occurrence of substance (cigarette, alcohol, marijuana and other drugs) use/abuse and internalizing disorders (depression and anxiety) in youth. The ultimate goal is to gain expertise in the relationship between substance use/abuse and other psychiatric disorders, especially internalizing disorders, and in the service needs and use of youth with comorbid substance abuse and internalizing disorders. The applicant's strong background of academic training in psychiatric epidemiology and research methodology in social sciences, and her research experience on risk factors for adolescent substance use, mental health service need and service use among depressed youth, and factors affecting adolescents receiving treatment for substance use related problems provides an excellent foundation for this work. The proposed training goals, including (1) increased knowledge about child and adolescent psychiatry, substance abuse and dependence; (2) enhanced skills in longitudinal survey methods and use of computerized survey instruments in collecting diagnostic information; and (3) advanced statistical training focusing on longitudinal data analysis of comorbidity, will all facilitate the applicant's pursuit of innovative, comprehensive, technologically efficient approaches in research on comorbidity. The research plan for this Award is divided into two studies which complement the proposed sequence of training activities and provide the applicant research experience with both clinical and community samples. In the first study, a clinical sample of 200 adolescents and one parent/guardian, originally interviewed twice in the Managed Care Study (1997-1999), will be re-interviewed with computerized instruments including the Diagnostic Interview Schedule for Children (DISC-IV), to assess prevalence and age of onset of psychiatric disorders, detailed questions about onset, frequency and quantity of substance use, family history of psychiatric disorders and substance use, as well as other familial and individual characteristics. In the second study, the applicant will use psychiatric assessment data (also DISC-IV) of 1500 Puerto Rican youth from an on-going three-wave community longitudinal study, including a set of questions contributed by the applicant, to study the relationship between substance use/abuse and internalizing disorders.